1. Field of the Invention
The present invention relates to a sock knitted and produced by a sock knitting machine, and a production method thereof.
2. Description of Related Art
Generally, a sock 101 as shown in FIG. 8 is knitted by a sock knitting machine using a circular knitting machine provided with a needle shuttle rotatably in forward and reverse directions, the needle shuttle having a plurality of knitting needles arranged on a circumference thereof. In knitting of the sock 101, as shown in FIGS. 9A to 9C, a toe housing portion 120 that houses a toe is knitted continuously with a cylindrically knitted portion 110 that forms a sole portion 111 and an instep portion 112.
In the knitting of the toe housing portion 120, generally, first, as shown in FIG. 9C, a back portion 121 of the toe housing portion 120 is knitted continuously with an end (an AB position) of the sole portion 111 of the cylindrically knitted portion 110. At this time, inversion knitting of alternately repeating forward rotation and reverse rotation of the sock knitting machine is performed, knitting needles that contribute to knitting at opposite inversion positions are reduced, for example, by one stitch (one wale) for each knitting course from a knitting needle region of a maximum knitting width toward a knitting needle region of a target minimum knitting width, and knitting is performed while gradually reducing the knitting width. When the knitting needle region of the minimum knitting width (a CD position) is reached, inversion knitting is performed continuously therewith toward the knitting needle region of the maximum knitting width contrary to the above as shown in FIG. 9A, knitting needles that contribute to knitting at opposite inversion positions are increased, for example, by one stitch (one wale) for each knitting course contrary to the above, and the front portion 122 of the toe housing portion 120 is knitted with gradually increasing the knitting width. At this time, opposite ends of the back portion 121 and the front portion 122 are connectedly knitted and connected. Reference numerals 124 and 124 in FIG. 9B denote the opposite connecting portions (gore lines). An end of the front portion 122 is finally connectedly knitted to an opening end of the instep portion 112 of the cylindrically knitted portion 110 and seamed together. Reference numeral 115 denotes the seam portion.
The conventional sock 101 knitted as described above has the toe housing portion 120 laterally symmetrical, and fits either right or left foot. However, the back portion 121 and the front portion 122 of the toe housing portion 120 are continuously folded back at a tip portion, and directly connectedly knitted at the opposite ends thereof, and a thickness (bulge) of the toe housing portion 120 is not very large. Thus, when a toe is housed in the toe housing portion 120, there is a feeling of tightness or pressure in a tip portion of the toe. Particularly, sock knitted fabric is stretched on the side of a thumb that is large and protrudes among fingers of a foot to cause a feeling of heavy pressure.
As a method for solving such a problem, a production method of a sock disclosed in Japanese Patent No. 2895473 has been proposed.
The proposed production method of a sock is basically a method of knitting by a sock knitting machine as is conventional. In knitting of a toe housing portion, while continuously knitting a back portion and a front portion of the toe housing portion by inversion knitting (between the back portion and the front portion), increase or decrease of knitting needles that contribute to knitting at laterally opposite inversion positions is changed to add a knitted fabric portion for increasing thickness on a thumb side, and a knitting direction for increasing thickness is shifted to the thumb side using a way of knitting of the added knitted fabric portion. Specifically, in the inversion knitting, the knitted fabric portion for increasing thickness is added to be slanted to the thumb side, and the knitted fabric itself is shifted in a stretched manner toward the thumb side. Also, due to the inversion knitting, the added knitted fabric portion is connectedly knitted with stitches changed to both the back portion and the front portion of the toe housing portion on the thumb side, and the connecting portions (gore lines) are branched.
In the proposed sock, the entire toe housing portion is shifted to the thumb side by the added knitted fabric portion, and the thickness and a radial bulge on the thumb side are increased, thereby preventing a feeling of tightness or pressure on the thumb side when the toe is housed. However, the branched connecting portions (gore lines) between the added knitted fabric portion and the back portion and the front portion of the toe housing portion are connected with the stitches changed and are conspicuous, a connection state is not very neat, the sock is poor in appearance, and the shift to the thumb side causes the knitted fabric itself to be tightened, thereby reducing commercial value. Also, for the added knitted portion, functions other than the function of increasing the thickness of the thumb side cannot be expected.